There's a clear distinction between people who don't know enough to ask a question well, or are new and don't get SO yet, and in this case I think they should get a lot of slack.
I have been seeing lots of cases of users basically asking me to do something, rather than to show them how to do it themselves. Many are experienced SO user, and existing content in the question provides the language they may need to do a simple google (usually finding a relevant SO answer!).
EDIT: In particular, I have seen this behavior in comment "threads" that follow on to an answer I (or someone else) provides. So the question starts out well enough, but the OP gets lazy in comments.
So what's the proper etiquette for saying "Yo, bozo, I am not a contract programmer thinking for you for free, figure it out given the 20 links and 30 snippets I have already posted"?
Perhaps something gentler and biblical like "I am here not to give you fish, but to teach you to fish"? Maybe there should be an auto-link or even a way of flagging that gives more experienced users the ability to flag a question as "LF!GF" (learn to fish, not give fish)